CN120642199A

CN120642199A - Power conversion device

Info

Publication number: CN120642199A
Application number: CN202380092982.9A
Authority: CN
Inventors: 田口友启; 石川祥甫
Original assignee: Anstemo Corp
Current assignee: Anstemo Corp
Priority date: 2023-03-22
Filing date: 2023-03-22
Publication date: 2025-09-12
Also published as: WO2024195062A1; DE112023005104T5; JPWO2024195062A1

Abstract

A power conversion device is connected and fixed to a motor housing that accommodates a motor, the power conversion device comprising: a housing having multiple side walls and an opening on the motor side; a cover covering the top surface of the housing; and multiple internal components housed in the housing, the multiple internal components including a capacitor, the housing having a connecting portion connected to the motor housing and multiple fixing portions for fixing the capacitor inside the housing, a first space portion being provided in the housing between the capacitor and the cover, and a second space portion being provided between the capacitor and the motor, the multiple internal components being arranged in a manner that connects a pair of opposite side walls among the multiple side walls.

Description

Power conversion device

Technical Field

The present invention relates to a power conversion device.

Background

Regarding the shape of a housing of a power conversion device of an electric vehicle or a hybrid vehicle, for example, patent document 1 discloses a power conversion device including a structure having a bottom surface for holding constituent members and securing strength.

Prior art literature

Patent literature

Patent document 1 Japanese patent laid-open publication No. 2013-115903

Disclosure of Invention

Problems to be solved by the invention

In patent document 1, since a large projected area is required for the bottom surface, the size of the casting machine becomes large, which causes an increase in cost. In addition, since the bottom surface exists in the case, the space inside or at the bottom of the case is divided, and the arrangement of the components is restricted, so that there arises a problem that the dimension in the height direction of the inverter increases. In addition, since the strength of the constituent members has been conventionally assembled individually one by one, it is difficult to secure mechanical strength.

Technical means for solving the problems

A power conversion device connected and fixed to a motor case accommodating a motor, the power conversion device including a case having a plurality of side walls and an opening on the motor side, a cover covering a top surface of the case, and a plurality of internal members accommodated in the case, the plurality of internal members including a capacitor, the case including a connection portion connected to the motor case and a plurality of fixing portions fixing the capacitor inside the case, a first space portion being provided between the capacitor and the cover, and a second space portion being provided between the capacitor and the motor, the plurality of internal members being arranged so as to connect a pair of opposite side walls among the plurality of side walls to each other.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a power conversion device that achieves cost reduction, miniaturization, suppression of strength reduction, and improvement of assemblability.

Drawings

Fig. 1 is an overall perspective view of the power conversion device.

Fig. 2 is an exploded view of fig. 1 in accordance with one embodiment of the present invention.

Fig. 3 is a cross-sectional view of the device of fig. 2, looking in the direction of arrow a, in accordance with one embodiment of the present invention.

Fig. 4 is a plan view of an inverter case according to an embodiment of the present invention.

Fig. 5 is a top view of one embodiment of the present invention as seen from the upper direction of the capacitor and a front view as seen from an arrow B.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description and drawings are examples for illustrating the present invention, and are omitted or simplified as appropriate for clarity of illustration. The invention may be embodied in other various forms. The constituent elements may be single or plural, as long as they are not particularly limited.

For easy understanding of the invention, the positions, sizes, shapes, ranges, and the like of the respective constituent elements shown in the drawings may not indicate actual positions, sizes, shapes, ranges, and the like. Accordingly, the present invention is not necessarily limited to the positions, sizes, shapes, ranges, etc. disclosed in the drawings.

(First embodiment and integral constitution of the invention)

(FIG. 1)

The bottom surface side of the inverter 1 is attached to the motor case 2 by a fastening mechanism such as a screw, and is connected and fixed. The motor case 2 accommodates a motor, not shown, and has a function as a base of the inverter 1 by connecting and fixing the inverter 1.

(FIG. 2)

The inverter 1 has a top cover 11 and an inverter case 17. The inverter case 17 is made of metal, and has a plurality of side walls and an opening 1c on the motor side (motor case 2 side), not shown. The inverter case 17 has a plurality of inverter components such as capacitors 16 mounted therein. The top cover 11 is installed in such a manner as to cover the top surface (upper surface of fig. 2) of the inverter case 17, thereby protecting the internal components of the inverter case 17. The inverter case 17 houses the LV connector 12, the ground board 13, the power module 14, the bus bar 15, and the capacitor 16 as internal components. In addition, the inverter case 17 has a DC connector 18 on the outer side of the side wall as a connection interface to be connected with an external component.

The LV connector 12 is a connection interface for connecting the inverter 1 to an external member on the top cover 11 side, and penetrates the top cover 11. The LV connector 12 may penetrate the top cover 11 at any position, or may penetrate the top cover 11 at another position.

The ground substrate 13 controls the inverter 1. The power module 14 converts electric power input to the inverter 1 and monitors electric current, and is integrated with a cooling water channel, not shown, flowing in the inverter 1. The bus bar 15 connects the power module 14 to a motor, not shown, mounted in the motor case 2. The capacitor 16 rectifies the electricity input from the outside of the inverter 1 via the DC connector 18 to flow to the power module 14. In addition, the capacitor 16 reduces radiation noise. The DC connector 18 is a connection interface that connects an external power source of the inverter 1 and the inverter 1.

(FIG. 3)

The inverter case 17 has a plurality of fixing portions 17b for fixing the capacitor 16 inside the inverter case 17. The capacitor 16 has fixing portions corresponding to the plurality of fixing portions 17b, and is connected and fixed to the power module 14 and the inverter case 17 by inserting fixing members 20 such as screws so as to align the fixing portions. The inverter case 17 has a case fixing portion 17a on the outside, and the connecting portion 3 is formed by inserting a fixing member or the like into the case fixing portion 17a and connecting the same to the motor case 2. In the internal space of the inverter case 17, an opening 1c is formed between the space of the capacitor 16 and the internal space of the motor case 2. The opening 1c will be described later with reference to fig. 4.

The inverter case 17 has a first space portion 1a and a second space portion 1b. The first space portion 1a is between the capacitor 16 and the top cover 11. The second space portion 1b is between the capacitor 16 and the motor housing 2 (or a motor not shown). By forming the first space portion 1a and the second space portion 1b in the inverter case 17, not only is it easy to arrange wiring for connection with the capacitor 16, but also connection of internal components in the inverter case 17 with a motor, not shown, housed in the motor case 2 is also easy. In addition, as will be described later in fig. 4, the capacitor 16 has a beam function of the inverter case 17, and contributes to securing the strength of the inverter case 17.

(FIG. 4)

The inverter case 17 has an opening 1c. The inverter case 17 includes a plurality of fixing portions 17a and a plurality of fixing portions 17b. The capacitor 16 is fixed in the inverter case 17 by a capacitor fixing portion 17b.

Since the bottom surface is provided on the inverter case 17 in the past, components mounted in the inverter case 17 can be mounted only in one direction. In addition, the bus bars disposed in the inverter case 17 require a step of forming holes in the bottom surface in order to connect to the motor side, and thus there is a problem in that the number of manufacturing steps increases.

However, as in the present invention, since the inverter case 17 has the opening 1c on the bottom surface, the degree of freedom in the order of assembling the internal components is increased by allowing the internal components to be mounted from either of the two surfaces of the inverter case 17, and the space in the inverter case 17 can be more easily and effectively utilized with respect to the component arrangement, so that the degree of freedom in the arrangement of the internal components is increased. Further, having the opening 1c increases the degree of freedom in arrangement of the bus bars disposed in the inverter case 17, and thus improves the space efficiency.

In addition, by providing the opening 1c in the inverter case 17, the projected area can be reduced, and the casting cost can be reduced and the weight can be reduced. Further, by providing the capacitor 16 in cooperation with the formation position of the opening 1c, the capacitor 16 functions as a structural member of the inverter case 17. Specifically, the capacitor 16 has a beam function of the inverter case 17 by being disposed so as to connect a pair of opposite side walls among the side walls of the inverter case 17. In addition, the power module 14 is provided in a position different from the position in which the capacitor 16 is provided in the inverter case 17, and thus the power module 14 functions as a beam as a structural member of the inverter case 17. Thereby, the strength of the inverter case 17 can be ensured by the respective internal components.

The power module 14 and the capacitor 16 function as a beam in the inverter case 17 by being mounted on the inverter case 17. The value of the natural frequency differs from one member to another. Therefore, even when one member resonates at the time of resonance in the power module 14 and the capacitor 16, the other member functions as a beam. This can attenuate the vibration of the side wall of the inverter case 17, suppress the deformation of the inverter case 17, and ensure the strength at the time of resonance.

In the plurality of fixing portions 17b provided in the inverter case 17, since it is necessary to fix the capacitor 16, the power module 14, and other components having weight in the inverter case 17, it is necessary to increase the strength of the fixing portions 17b themselves. Accordingly, since the strength of the fixing portion 17b is higher than that of the side wall, the rigidity of the side wall of the inverter case 17 is lower than that of the fixing portion 17b, and the force applied to the wall surface of the inverter case 17 can be transferred to the internal component side through the fixing portion 17 b. Further, by increasing the rigidity of the fixing portion 17b, the transmission of vibration and impact to the capacitor 16 can be prevented, and not only the strength of the wall surface itself can be ensured, but also the improvement of the vibration resistance can be facilitated.

As a method for improving the rigidity of the fixing portion 17b, for example, the fixing portion 17b may be formed in a thick wall shape or a rib shape formed on the outer peripheral side (side wall outer side) of the fixing portion 17b to ensure high mechanical strength.

Further, the structure of the fixing portion 17b also helps to solve the problem of the strength of the inverter case 17 being lowered due to the opening portion 1c. Specifically, the wall surface of the inverter case 17 having a lower strength than the fixing portion 17b can be thinned. Further, since the inverter case 17 has the opening 1c and is elastically deformed, for example, an effect of absorbing vibration and shock transmitted from the motor can be achieved, and the shock generated in the fixing portion 17b can be also relaxed.

Further, by providing the opening 1c, even in the layout of the bus bars and wires connected to the motor side, it is not necessary to consider the machining accuracy related to the tolerance of the hole on the inverter case 17 side, and the layout load can be reduced by coping with only the positional tolerance of the bus bars. That is, the inverter case 17 does not have a bottom surface, so that the connectivity between the internal components of the inverter case 17 and the components disposed on the motor side is improved, and the efficiency of the space inside the inverter case 17 can be easily improved.

(FIG. 5)

Fig. 5 (a) is a plan view of the capacitor 16 as seen from the upper surface thereof, and is an explanatory view of a plurality of fixing portions 20a to 20e provided on the capacitor 16, and fig. 5 (B) is a front view of the capacitor 16 as seen from the direction B of fig. 5 (a).

The capacitor 16 has fixing portions 20a to 20e for fixing to the inverter case 17. The connection between the capacitor 16 and the inverter case 17 does not necessarily need to be made by screws or the like, and may be made by, for example, setting up bolts or the like on the inverter case 17 side and fixing them with nuts, or by providing a snap-fit structure on the inverter case 17 or the capacitor 16, and by fitting and fixing them.

A measure against lateral shake of the inverter case 17 will be described. The fixing portions 20a to 20e shown in fig. 5 (a) and 5 (b) are provided so that the distance between the fixing portions that are adjacent to each other is as short as possible.

In the capacitor 16, the fixing portions 20a and 20b are fixed to each other. In this way, by fastening the fixing portions 20a to each other, the truss shape is formed by the pair of fixing portions 20a and the corner portions 16b of the capacitor 16, so that the strength of the capacitor 16 and the inverter case 17 can be ensured, and the vibration of the whole can be suppressed. Similarly, by fastening the fixing portions 20b to each other, the truss shape is formed by the pair of fixing portions 20b and the corner portions 16a of the capacitor 16, so that the strength of the capacitor 16 and the inverter case 17 can be ensured, and the vibration of the whole can be suppressed.

Further, by tightening the fixing portion 20c shown in fig. 5 (a), the fixing portion 20c and the fixing portion 20d and the corner portion 16a formed in the width direction of the capacitor 16 near the fixing portion 20c form a small truss shape, and therefore vibration of the corner portion 16a of the capacitor 6 can be suppressed. Similarly, by tightening the fixing portion 20d, the fixing portion 20d and the fixing portion 20a and the corner portion 16b formed in the width direction of the capacitor 16 near the fixing portion 20d form a small truss shape, and therefore vibration of the corner portion 16b of the capacitor 6 can be suppressed. This ensures the strength of the capacitor 16 in the inverter case 17, and further expands the range of influence of the internal components in the inverter case 17 functioning as beams, and further ensures the strength.

In addition, in the case where the capacitor 16 is fixed to the inverter case 17 by as few fixing members as possible, fastening of the fixing portions 20a and 20b to each other is prioritized over fixing of the fixing portions 20c and 20d, and thus strength can be ensured reliably.

Next, measures against longitudinal vibration of the inverter case 17 will be described with reference to a plurality of fixing portions 20a to 20e shown in fig. 5 (b). The plurality of fixing portions 20a to 20e include a combination of fixing portions provided at mutually different positions in the thickness direction of the capacitor 16. Specifically, the group of fixing portions 20b shown in fig. 5 b (the other group is shown in fig. 5 a), the group of fixing portions 20c and 20d, and the group of fixing portions 20a and 20e are 3 groups. This makes it possible to fix the capacitor 16 uniformly to the inverter case 17 and to have strength.

In addition, in fig. 5 (b), the truss-like shape is formed by the fixing portion 20a, the fixing portion 20b, and the corner portion 16c, and the two most separated points of the both end portions of the capacitor 16 can be connected, so that the beam action of the capacitor 6 in the inverter case 17 can be provided, vibration resistance can be improved, and the influence range functioning as a beam can be widened.

In addition, in fig. 5 (b), the fixing of the central portion of the reinforced capacitor 6 can be achieved by the fixing portions 20a and 20c and the fixing portions 20d, 20e and 20b, and therefore the strength of the capacitor 16 can be further ensured.

As a countermeasure against the natural vibration (countermeasure against resonance) of the inverter case 17, the plurality of fixing portions 20a to 20e include a combination of fixing portions 20a to 20e arranged at the same position in the thickness direction of the capacitor 16, as shown in fig. 5 b, considering that portions that are liable to vibrate in the respective vibration modes are different. Specifically, in the thickness direction of the capacitor 16, the fixing portions 20b are aligned at the same positions as each other, and the fixing portions 20c and 20d are aligned at the same heights, and the fixing portions 20a and 20e are aligned at the same heights. Thus, the assembling property can be improved.

In this way, the above-described configuration of the plurality of fixing portions 20a to 20e provided in the capacitor 16 eliminates the risk of insufficient strength due to the opening 1c of the inverter case 17, and further, the inverter case 17 and the motor case 2 are fastened to each other, so that strength equivalent to the bottom surface can be ensured, and strength and sealing performance can be ensured.

In addition, in the case where the inverter 1 is fixed too firmly, even when vibration or impact is directly transmitted to the fixing portion, the inverter case 17 is elastically deformed by the configuration of the present invention, and therefore, an effect of relaxing the impact can be expected.

According to the embodiments of the present invention described above, the following operational effects are achieved.

(1) A power conversion device connected and fixed to a motor case 2 for housing a motor is provided with a case 17 having a plurality of side walls and an opening on the motor side, a cover 11 covering the top surface of the case 17, and a plurality of internal components housed in the case 17. The plurality of internal components include a capacitor 16, and the case 17 includes a connection portion 3 connected to the motor case 2 and a plurality of fixing portions 17b for fixing the capacitor 16 inside the case 17. In the case 17, a first space portion 1a is provided between the capacitor 16 and the cover 11, and a second space portion 1b is provided between the capacitor 16 and the motor, and a plurality of internal members are arranged so as to connect a pair of opposite side walls among the plurality of side walls to each other. This can reduce the number of reinforcing members such as the bottom plate, reduce the impact on the fixing portions 20a to 20e and the capacitor 16, improve the wiring layout, and reduce the cost due to the reduction in tolerance.

(2) In the inverter case 17, the rigidity of the side wall is lower than the rigidity of the fixing portions 20a to 20 e. This can reduce the weight of the inverter case 17, and strengthen the rigidity of the fixing portions 20a to 20 e.

(3) The capacitor 16 is disposed in such a manner as to connect the opposite pair of side walls among the plurality of side walls to each other. Thereby, the strength of the inverter case 17 can be ensured.

(4) A pair of the plurality of fixing portions 20a to 20e and a corner portion of the capacitor 16 form a truss shape when viewed from the lid 11 side. This ensures the strength of the members in the capacitor 16, and can expand the range of influence of the beam.

(5) The plurality of fixing portions 20a to 20e include a combination of fixing portions provided at mutually different positions in the thickness direction of the capacitor 16. This ensures the strength of the members of the capacitor 16, and can expand the range of influence of the beam.

(6) The plurality of fixing portions 20a to 20e include a combination of fixing portions arranged at the same position in the thickness direction of the capacitor 16. This ensures the strength of the members of the capacitor 16, thereby expanding the range of influence of the beam and ensuring manufacturability.

The present invention is not limited to the above-described embodiments, and various modifications and other configurations may be combined within a range not departing from the gist thereof. The present invention is not limited to the configuration having all the configurations described in the above embodiments, and includes a configuration in which a part of the configurations is deleted.

Symbol description

1. The inverter includes an inverter 1a, a first space portion, 1b, a second space portion, 1c, an opening portion, 2, a motor case, 3, a case connection portion, 11, a top cover, 12, an LV connector, 13, a ground substrate, 14, a power module, 15, bus bars, 16, capacitors, 16a to 16c, corners, 17, an inverter case, 17a, a case fixing portion, 17b, a capacitor fixing portion, 18, a DC connector, 20, a fixing member, 20a to 20e, and a fixing portion.

Claims

1. A power conversion device connected and fixed to a motor housing that houses a motor, characterized in that the power conversion device comprises:

a housing having a plurality of side walls and an opening on the motor side;

a cover covering a top surface of the housing; and

a plurality of internal components housed within the housing,

The plurality of internal components include capacitors,

The housing includes a connection portion connected to the motor housing and a plurality of fixing portions for fixing the capacitor inside the housing.

In the housing, a first space is provided between the capacitor and the cover, and a second space is provided between the capacitor and the motor.

The plurality of internal components are arranged so as to connect a pair of opposing side walls among the plurality of side walls.

2. The power conversion device according to claim 1, wherein:

The rigidity of the side wall is lower than the rigidity of the fixing portion.

3. The power conversion device according to claim 1, wherein:

The capacitor is arranged so as to connect the pair of opposing side walls among the plurality of side walls.

4. The power conversion device according to claim 1, wherein:

A pair of the plurality of fixing portions and a corner portion of the capacitor form a truss shape when viewed from the cover side.

5. The power conversion device according to claim 1, wherein:

The plurality of fixing portions include a combination of the fixing portions provided at positions different from each other in the thickness direction of the capacitor.

6. The power conversion device according to claim 1, wherein:

The plurality of fixing portions include a combination of the fixing portions arranged at the same position in the thickness direction of the capacitor.